The present invention relates to a weighing and computing system of the type which determines a net weight and net price for each commodity in a series of commodities to be weighed and a total net price for the entire series of commodities. The present invention is more particularly directed to a digital weighing and computing system which differentiates between items to be weighed and items of fixed net price which are not to be weighed for providing a total net price for the entire series of commodities which includes the items to be weighed and items of fixed net price which are not to be weighed.
Automatic weighing, price computing and price registering systems are well known. Such a system is fully disclosed and claimed in Karp, U.S. Pat. No. 3,262,639 which issued July 26, 1966 and which is assigned to the assignee of the present invention. The system there disclosed is one which includes an optical angular shaft position encoder which provides a signal indicative of the load placed onto the weighing platform of the weighing mechanism and which additionally registers for storing the tare weight of packaging material and the gross weight of a commodity and its package. The system disclosed in the aforementioned patent additionally includes a subtractor for determining the difference between the gross weight and tare weight to provide a net weight of the commodity and a multiplier for multiplying the net weight by a unit weight price for determining the net price of the commodity.
Like other weighing and computing systems which have come before, the system disclosed in U.S. Patent No. 3,262,639 is incapable of providing a total price for a sum of commodities to be weighed and in so doing, allowing each previously weighed commodity of the series to remain on the weighing mechanism platform as subsequent commodities are weighed. In commercial weighing operations, and particularly in retail food operations, a customer may wish to purchase more than one commodity item. In this environment, considerable time would be lost if each item had to be weighed separately for determining a net weight and then computing a total net price on another computing system. Also, in the retail food environment, a customer may wish to not only purchase a number of commodity items which must be weighed in determining a net price for each, but additionally items of fixed net price. Prior weighing and computing systems have been incapable of differentiating between commodities to be weighed and commodities of fixed net price not to be weighed rendering them unsuitable for the computing of a total net price for all of the commodities to be weighed and those of fixed net prices.
Retail food store owners in the past, when serving a customer purchasing a plurality of items to be weighed and one or more items of fixed net price have had to determine a net weight and price separately for each commodity item to be weighed and then to total the prices of all of the commodity items including those which have been weighed and those of fixed net price on a separate computing mechanism such as a cash register. Obviously, this requires a significant number of operational steps which can cause consumers considerable waiting time for a total net price to be computed and long lines at the counter.
Prior art weighing and computing systems of the digital type have other deficiencies in addition to those previously discussed. Prior art digital scales display the instantaneous weight of the item being weighed continuously while the weighing mechanism is coming to rest. The weights are displayed at such a rapid rate that the human eye cannot distinguish between successive displayed weights until the scale has come to rest. This can be confusing and disturbing to both the user and the customer. Additionally, in retail food operations the weighing and computing systems may be located on or near a refrigerator or other vibrating device causing the displayed weight to change continuously even after the scale platform has nominally come to rest. Prior art weighing and computing digital systems continuously compute net price, not only resulting in the displayed net weight changing but additionally in the net prices changing. This can cause embarrassment to merchants and also cause consumers to believe that the price that they are paying may be incorrect.
It is therefore a general object of the present invention to provide a weighing and computing system which determines a net weight and net price for each commodity in a series of commodities to be weighed and a total net price for the entire series of commodities weighed.
It is also a general object of the present invention to provide a digital weighing and computing system of the type which determines a net weight and net price for each commodity to be weighed in a series of commodities and a total net price for an entire series of commodities which includes commodity items to be weighed and commodity items of fixed net price which are not to be weighed.
It is a still further object of the present invention to provide a digital weighing and computing system which displays the net weight of a commodity being weighed at periodic intervals such that each net weight displayed is individually discernible.
It is a still further object of the present invention to provide a digital weighing and computing system which displays a relatively continuous and unchanging net weight and net price for each commodity item weighed once the weighing mechanism platform has nominally come to rest.
It is a still further object of the present invention to provide a digital weighing and computing system which computes average net weights during predetermined time intervals to thereby accelerate the final net weight determination and to render the system less sensitive to minor external vibrations.